Truck body hoist mechanism



Oct. 29, 1940. G MAXQN JR TRUCK BODY HOIS T MECHANISM Filed Jan. 27, 1939 4 Sheets-Sheeti 'FIG. I.

I INVENTOR I I 1"" I I BY ATTORNEY G. MAXON, JR ,219,525

TRUCK BQDY HOIST MECHANISM Filed Jan. 27, 1939 4 Shee ts-Sheet 2 FIG. 4. I FIG. 5.

I ma:

ATTORNEY Oct. 29, 1940. G MAXON' JR 2,219,525

TRUCK BODY HOIST MECHANISM Oct. 29, 1940- G MAXON, JR 2,219,525

1 mm BODY HOIST MECHANISM Filed Jan. 27, 1939 4 Sheets-Sheet 4 FIG.8.

ATTORNEY Patented a. 29, 1940 UNITED STATES PATENT oFFics 11 Claims.

The invention relates to truck bodies and other containers.

One of the objects of the invention is to provide a hoisting mechanism which will increase the range of lift of the body while the hoisting cylinder or cylinders is or are located in a horizontal plane which permits the mechanism with its subframe being fitted to a great number of "different makes of truck frames 'without alteration.

Another object of the invention is to increase the lifting capacity of the hydraulic cylinder or cylinders by providing for maintaining a substantially constant hydraulic pressure for a given load throughout the hoisting operation.

Another object of the invention is to provide a hoisting mechanism including arms connecting the truck body with the truck frame or chassis and disposed to operate in planes outside of said truck frame which facilitates the installation of said mechanism on a truck.

A further object of the invention is to provide a hoisting mechanism including arms which have parts operating on horizontal and vertical tracks which permits the hoisting mechanism to adjust itself to the twisting of the automobile chassis in reference to the rigidity of such a structure as a hopper bottom body.

A further object of the invention is to provide a hoisting mechanism including sets of arms operatively connected to the body and to each other withvone set also connected with a horizontally disposed hydraulic hoisting means.

A further object of the invention is to provide a hoisting mechanism including arms cpnnecting the truck body with the truck frame or chassis whereby the body may be elevated above said truck frame and inclined at an angle thereto, the arrangement being such that the dumping angle of the body can be varied. A further object of the invention is to provide a hoisting mechanism for an end dump truck body in which the center of gravity of .the truck body is restrained from the usual rearward movement and the lifting mechanism includes levers at the rear which are so constructed that they move the pivot points at the rear of the truck forwardly before an angle of the body sufficiently steep has been reached as to cause the material in the truck to start sliding rearwardly. A further object of the invention is to provide a hoisting mechanism for truck bodies which will permit the direct upward lift of the body for 55 certain kinds of material and also a rearwardly inclined dumping position for other kinds of material.

The invention further consists in the several features hereinafter .set forth and more particularly defined by, claims at the conclusion 5 hereof.

In the drawings:

Fig. l is a side elevation view of a truck body hoist mechanism embodying the invention with the body in lowered position;

Fig. 2 is a view similar to Fig. 1, showing the parts in a partially raised position, parts being broken away;

Fig. 3 is a horizontal sectional the broken line 3-3 of Fig. 1;

Fig. 4 is a detailed vertical sectional view taken on the line 4-.4 of Fig. 1;

Fig. 5 is a detailed horizontalsectional view taken on the line 55 of Fig. 1; I

Fig. 6 is a view similar to'Fig. 1 showing certain modifications;

Fig. '7 is a view similar to Fig. 6 showing the body in one of its raised positions;

Fig. 8 is a view similar to Fig. 1 showing the' invention applied to an inclinable dump body, the body being in lowered position;

Fig. 9 is a view similar to Fig. 8 with the body in raised position, parts being broken away;

Fig. 10 is a detailed horizontal sectional view taken on the line iii-ill of Fig. 9.

Referring to the drawings, the numeral Ill designates the main truck frame or chassis supported by the-wheels C in any suitable manner, and in Figs. 1 to 3, inclusive, ii a subframe formed of longitudinal frame members l2 and cross frame members it. The subframe also includes frame members I cooperating with the tops of frame members i2 to form tracks or guides I5 at the forward portion of the subframe. Frame members i6 on the members l2 and frame members I'l secured thereto cooperate to form tracks or guides l8. Also at each side of the subframe at the front of the vehicle inclined tracks i9 are provided, and at the rear of the subframe inclined tracks 20 are provided.

A set of arms 2i is mounted at the forward part of the subframe, and a set of arms 22 is mounted at the rearward part of the subframe, these arms being operatively connected together and to the truck body. '60 .The arms 21. are connected together by a cross shaft 23 which adjacent each arm 2i carries a roller 24 which roller operates on the guide ill at the forward portion of the subframe. Each arm II also carries aroller 25 which engages the view taken on vertically disposed inclined track l9. The shaft 23 also has collars 26 which are connected to the rods 21 of the hydraulically operated pistons 28 which work in the cylinders 29 mounted on the subframe in a substantially horizontal posi-- tion.

The arms 22 are connected together by a cross shaft 30 which adjacent each arm' 22 carries a roller 3| which roller operates on the guide I8 at the rear portion of the subframe. Each arm 22 also carries a roller 32 which engages the vertically disposed inclined track 20-.

The outer ends of the shafts 23 and 30 are connected together by links 33.

. The truck body 34 has vertically disposed sets of frame members or uprights 35 and 36, the uprights 35 being pivotally connected to the arms 2| at 31 and the uprights 36 being pivotally connected to the arms 22 at 38.

The arms 2| and 22 form in effect bell crank levers in which the rollers, the connecting shafts, and the connections with thetruck body are at spaced points.

Each arm 2 -is preferably formed by a pair of spaced metal plates 39 between which the roller 25 and the end of upright 35 is mounted.

Each arm 22 is preferably formed by a pair of spaced metal plates 39 between which the roller 32 and the end of the'upright 36 is mounted.

It is also to be noted that the arms 2| and 22 are mounted to swing on their connecting shafts in planes outside of the subframe and chassis frame of the truck so that the hoisting mechanism above described may be readily applied to a great number of different makes of trucks without the necesity of altering the subframe.

It is also to be noted that the tracks l3 and 20 are inclined tracks, and these are specially formed so that for equal increments of lift there will be equal increments of cylinder displacement so that the hydraulic pressure for any given load will be kept substantially constant. This permits substantially the full efiiciency of the hydraulic hoisting mechanism to be utilized, and said mechanism does nothave to be overpowered to take care of a relatively high pressure at one point in the lifting cycle.

With the above described arrangement when hydraulic fluid is introduced into the closed end of the cylinders 29, the pistons 28 are moved outwardly, thus shifting the shaft 23 forwardly and hence moving the arms 2| forwardly along the tracks I 5. This movement at the same time causes a movement of the rollers 25 along the tracks I9 causing a swinging movement of the arms 2| about the shaft 23 as a pivot and thus causing the lower ends of the arms 2| to swing upwardly and lift the forward end of the body 34. Simultaneously with the movement of the arms 2|, the arms 22 through the links 33 are moved forwardly along the tracks l8, and at the same time the rollers 32 engage the tracks 20 and move along the same causing a swinging movement of the arms 22 about the shaft 30 as a pivot and thus causing the lower ends of the arms 22 to swing upwardly and lift the rear end of the body. The lifting movement of the arms 2| is equal to that of the arms 22 so that the truck body 34 is lifted vertically upward, it being noted that because of the shape of the tracks l9 and 20 the pressure of the hydraulic fluid acting on the pistons 28 will be constant for equal increments of lift of the truck body when the hydraulic fluid is released from the closed end of said cylinders and is permitted to flow into the front end of the cylinders 29, the shafts 23 and 3|) will be moved rearwardly, and the arms 2| and 22 will then be moved laterally and swung downwardly to lower the body 34, It is also to be noted that by checking the passage of fluid from the closed end of the cylinders 29, the pistons 28 may be held in a stationary position, and consequently the body 34 may be held in different positions of elevation. The particular devices for furnishing the hydraulic fluid form no part of the present invention, but in Fig. 3 I have shown a pump P driven through a universal joint J and shaft S suitably connected with the power plant of the truck, said pump connected with a control valve V provided with an operator controlled lever O, there being piping T connected with the ends of the cylinders and with the control valve and pump. The arrangement is such that for one position of the lever 0 the hydraulic fluid is delivered to the closed ends of the cylinders 29 for hoisting while being relieved from the front ends, and in another position no fluid is delivered to the closed ends and the piston is held stationary, and in the third position the fluid is relieved from the closed end and permitted to flow into the front end of the cylinders. It is to be noted that the front ends of the cylinders act as reservoirs.

It is also to be noted that the body 34 is a hopper bottom body with a central discharge opening in its bottom.

The form shown in Figs. 6- and 7 is the same as that previously described except that provision has been madefor securing a tilting adjustment in addition to a direct upwardly lift. Those parts that are identical with the first described construction will be designated by the same numerals.

Referring to the drawings, the truck frame ||l supports the subframe similar to the first described construction having the guides l5 and I8 and which also has the inclined tracks l9 provided at each side at the front of the vehicle and inclined tracks 20 at each side of the rear portion of the subframe.

A set of arms 2| is mounted at the forward part of the subframe, and a set of arms 22' is mounted at the rearward part of the subframe, these arms being operatively connected together and to the truck body.

The arms 2| are connected together by the cross shaft 23, as in the first described construction, which shaft adjacent each arm 2| carries a roller 24 which operates on the guide l5 at the forward portion of the subframe. Each arm 2| also carries a roller 25 which engages the vertically disposed inclined track 9. The shaft 23 is operatively connectedin the same way as the first described construction to the rods 21 of the hydraulically operated pistons 28 which work in the cylinders 28 mounted in the subframe in a substantially horizontal position.

The arms 22 are generally similar to the arms 22 and are connected together by a cross shaft 30, as in the first described construction, which shaft adjacent each arm 22 carries a roller 3| which roller operates on the guide l8 at the rear portion of the subframe. Each arm 22' also carries a roller 32 which engages the vertically disposed inclined track 20.

The outer ends of the shafts 23 and 30 are connected together by links 33.

The truck body 34 has vertically disposed sets of frame members or uprights 35' and 36, the uprights 35' being pivotally connected to the arms 2| at 31 and the uprights 36 being pivotally connected to the arms 22' at either the points 38', 40, or 4| byv a pin 42, it being noted that when the pin 42 is in the aligned set of holes 38 in the upright and arm that the holes 40 in said upright and arm are aligned with each other and that the holes 4| in said'upright and arm are in line with each other.

As in the first described construction the arms 2! and 22' are mounted to swing on their connecting shafts in planes outside of the subframe and chassis frame of the truck, and the tracks l9 and 20 are identical with those previously described so that for equal increments of lift for a directly vertical lift there will be equal increments of cylinder displacement, so that the hydraulic pressure for any given load will be'kept substantially constant.

. With the above arrangement when the pin 42 is disposed in the lower end of the upright 35 and the arm 22' in the holes 38, the linkage will be arranged as in the. first described construction and operate in the same manner with the same advantages to lift the body straight up and down,

.the arm 22' and upright 35 then acting the same as the arm 22 and the upright 35 even though the upright 36' is pivotally connected-at "to the truck body, the raised position of the body being shown in dotted lines in Fig. 6. This method of hoisting may be used when the material within the body is to be discharged or removed at a higher level than the ground level, for example, an elevated platform.

When it is desired to provide an end dump body, the pin 62 is shifted to either of the sets of holes dd or ii, and in Fig. 7 I have shown the. pin 42 disposed in the upper set of holes 41 in the arm 22' and the upright 38. Under these conditions when hydraulic fluid is introduced into the closed end of the cylinders 29 and the pistons 28 and shaft 28 are moved outwardly, the arms 2! are moved forwardly along the tracks l5 while at the same time the rollers 25 move along the tracks is causing a swinging movement of the arms 2| about the shaft 23 as a pivot and thus causing the lower ends of, the arms 2i to swing upwardly and lift the forward end of the body 34. Simultaneously with the movement of the arms 2|,the arms 22 through the links 33 are moved forwardly along the tracks l8, and at the same time the rollers 32 engage the tracks 20 and move along the same causing a swinging movementof the arms 22 about the shaft 30 as a pivot and thus causing the lower ends of the arms 22 to swing upwardly and lift the rear end of the body as shown in full lines in Fig. 7. The lifting movement of the arms 22' under thisposition of adjustment is less than that of the arms 2|, so thatthe truck body v34 is lifted upwardly but with the rear end of the body inclining downwardly for discharging its contents from an opening in the rear end of said body. It is-to be noted that with this construction during the lifting movement of the rear end of the body, said body through the movement of the arms 2| and 22' along the tracks l5 and I8 is moved forwardly, so that the center of gravity of the body is shifted forwardly, and this occurs principally before the load is inclined to a position where it will start to shift, and this greatly increases the stability of the construction over the usual designs.

It is also to be'noted that while the rear end of the. body is not lifted the equal amounts for equal amounts of piston displacement of the hydraulic cylinders 29, the fact that this end is not lifted as high as the front end compensates for In the form shown in Figs. 8 to 10, inclusive,

the lifting of the front end of the truck body is similar to that of the first construction, but the rear hoist mechanism is modified so that less lift is imparted to the rear end of the truck body, and consequently the body is tilted rearwardly during the hoisting operation.

Referring to Figs. 8 to 10, inclusive, the subframe 44 carries the vertically disposed specially curved tracks 45 and tracks or guides 41!.

A set of arms 48 is mounted at the forward part of the subframe, and a set of arms 49 is mounted at the rearward part of the subframe, these arms being operatively connected together and to the truck body.

The arms 48 are connected together by a cross shaft 50 which adjacent each arm carries a roller 5! which roller operates on the guide 41 at the forward portion of the subframe. Each arm 48 also carries a roller 52 which engages the track 45. The track 45 is so formed as to provide equal increments of lift for equal increments of piston displacement, so that the pressure of the hydraulic fluid may be kept substantially constant during the lifting 'operation. The shaft 50 has a collar 58 mounted thereon centrally thereof which is connected to the rod 54 of the hydraulically operated piston 55 which works in the cylinder 55 mounted on the subframe in a substantially horizontal position.

The arms 49 are connected together by a cross shaft 51, and at a point 58 spaced therefrom each arm is vertically pivotally connected to the subframe 44.

The truck body 59 has links 60 pivotally connecting its forward end to the arms 48 at 8| and upright frame members 82 pivotally connected at 63 with the arms 48. I The shafts 50 and 51 are connected together by links 84.

The arms 48 and 49 in effect form bell-crank levers as in the first construction, but the levers 49 are not guided by tracks but simply turn about the pivots 58 as centers. The arms as in the previous construction are formed of spaced plates in which the parts connecting them with the truck body are mounted.

It is also to be noted that the curved tracks 45 are so formed that for equal increments of lift at the front end of the truck there will be equal increments of piston displacement, so that for any given load the hydraulic pressure will be kept constant.

With the above described arrangement when the piston 55 is moved forwardly in its operating cylinder 56, the shaft 50 is shifted forwardly and hence the arms 48 are moved forwardly along the tracks 41. This movement at the same time causes a movement of the rollers 52 along the tracks 45 causing the lower end of said arms to swing upwardly about the rod or shaft 50 as a pivot and acting through the links to raise the front end of the body 58 upwardly. Simultaneously with the movement of the arms 48, the links 64 pull the shaft 51 forwardly, thus causing the arms 49 to swing about the pivot 58 and thus raising the pivot 63 upwardly and consequently the uprights 52 raising the lower end of the body 59 upwardly, but as the lift produced by the arms 48 is less than that effected by the arms 48 the truck body 58 is elevated to an inclined position in which the rear end is lower than the front end so that material in the body will gravitate to the rear end and be discharged through an opening (not shown) in said end.

When the hydraulic fluid is introduced into the front end of the cylinder 56 while being released from the rear end of said cylinder, the shaft 50 will be moved rearwardly, and the arms 48 and 49 will then be operated to lower the body to its initial position.

It is also to be noted that by checking the passage of fluid from both sides of the cylinder the piston 55 may be held in a stationary position, and consequently the body may be held in different positions of elevation.

For providing for a different inclination of the body the pivot 63 may be shifted or adjusted relative to the lever 49 and upright 62, so that the pin forming said pivot may be inserted in the then aligned holes 65 in said lever and upright in the lowered position of said body and provide for the lifting of the body to the raiseds inclined position shown in dotted lines in Fig. 9. It will be noted that in each .of the forms de scribed above at least one set of levers has a pivot which has a straight line movement and a' fulcrum point which moves at a predetermined angle to said straight line movement and preferably at such an angle as to provide equal increments of lift for equal piston displacement of the hydraulic hoisting mechanism. Where the lift of the body is straight up, both sets of levers are similar, and where the lift is on an incline, one set of levers provides for a lower total lift than the other.

I desire it to be understood that this invention is not to be limited to any particular form orarr'angement of parts except in so far as such limitations are included in the claims.

What I claim as my invention is:

1. In a device of the character described, the combination of a supporting frame, a body having a discharge opening, and means for lifting said body to permit gravity discharge from said opening comprising levers operatively connected to each other and to the front and rear portions of said body and to said frame, piston type hydraulically operated means connected with one set of said levers to actuate the same, said last named set of levers having a pivot portion with a movement along said frame and means for reacting with said last named set of levers to provide equal increments of lift for equal increments of piston displacement of said hydraulically operated means.

2. In a device of the character described, the combination of a supporting frame, a body having a discharge opening, and means for lifting said body to permit gravity discharge from said opening comprising sets of bell-crank levers at the front and rear portions of said frame, shafts connecting the pivot points of each set of levers, links operatively connecting said shafts, means for operatively connecting said levers to said body, and hydraulically operated means connected with one of said shafts for operating said levers. i

3. In a device of the character described, the combination of a supporting frame, a body having a discharge opening, and means for lifting said body to permit gravity discharge from said opening comprising levers operatively connected to each other and to the front and rear portions of said body and to said frame, said levers hav-.

"ing points about which they pivot and points about which they fulcrum, the connections for said levers with said frame at the front of said body including means for moving the pivots of said-levers along a straight path and means for causing the fulcrum points of said last named levers to. move at an angle to said straight path.

4. In a device of the character described, the combination of a supporting frame, a body having a discharge opening, means for lifting said body to permit gravity discharge from said opening comprising .levers operatively connected to each other and to the front and rear portions of said body and to said frame, said levers having points about which they pivot andpoints about which they fulcrum, the connections of said levers at the front of said body including piston type hydraulically operated means for moving the pivots of said levers along a straight path, and means for causing the fulcrum points of said last named levers to move at a predetermined angle to said straight path so that equal increments of piston displacement of said hydraulically operated means will produce equal increments of lift of said body.

5. In a device of the character described, the combination of a supporting frame, a body having a discharge opening, and means for lifting said body to permit gravity discharge from said opening comprising sets of bell-crank levers at the front and rear portions of said frame, shafts connecting the pivot points of each set of levers and movable longitudinally relative to said frame, links operatively connecting said shafts together, hydraulically operated means connected with one of said shafts for operating said levers, and means for operatively connecting said levers to said body including means controlling the movement of said levers for imparting equal increments of lift to said body while maintaining the pressure of the hydraulic fluid for said hydraulically operated means substantially constant.

6. In a device of the character described, the combination of a. supporting frame, a body having a discharge opening at one end, and means for lifting and tilting said body downwardly at its discharge end comprising sets of bell-crank levers at the front and rear portions of said frame, shafts connecting the pivot points of each set of levers together, the forward levers being longitudinally movable relative to said frame, links operatively connecting said shafts together, hydraulically operatedmeans connected with the shaft for the forward set of levers, and means for operatively connecting said levers to said body including means controlling the movement of said levers for imparting equal increments of lift to theforward end of said body while maintaining the pressure of the hydraulic fluid for said hydraulically operated means substantially constant.

7. In a device of the character described, the combination of a supporting frame, a body, and means for lifting said body to an unloading position comprising sets of levers at the front and rear portions of said frame, shafts connecting the pivot points of each set of levers, links operatively connecting said shafts, means for moving one of said shafts to raise and lower said levers, and means for operatively connecting said levers to said bodyincluding means for guiding said shafts for the pivot points of said levers along said frame and means for controlling the turning movements of said levers about their pivots, the connections between said levers and said body direct upward lift of' said bodyor lifting to an lowermost.

8. In a device of the character described, the

- combination of a supporting frame, a body having a discharge opening at one end, and means for lifting and tilting said body downwardly at its discharge end comprising sets of bell-crank levers at the front and rear portions of said frame, shafts connecting the pivot points of each set of levers together, the forward levers being longitudinally movable relative to said frame, links operatively connecting said shafts together, hydraulically operated means connected with one of said shafts for operating said levers, means for operatively connecting said levers to said frame, and means for operatively connecting said levers to said body, said last named means for the levers at the rear portion of said frame being adjustable to permit tilting of said body to different inclinations.

9. In a device of the character described, the combination of a supportingframe, a body, and means for lifting said body comprising levers operatively connected to each other and to the front and rear portions of said body and to said frame, said levers having points about which they pivot and points about which they fulcrum, the connections for said levers with saidframe each including means for moving the pivots of said levers along a straight path and means for causing the fulcrum points of said last named levers to move at an angle to said straight path.

opening including levers 10. In a device of the character described, the combination of a supporting frame, a body having a discharge opening, and means for lifting said body to permit gravity discharge from said connecting the front portion of said body to said frame, said levers having points about which. they pivot and having fixed fulcrum points, and connections for said levers with said frame including means for moving thepivots of said levers along a straight path and track means of said levers to move path.

11. In a device of the character described, the combination of a supporting frame, a body havopening, and means for lifting said body to permit gravity discharge from said opening including levers connecting the front portion of said to said frame, said levers having points about which they pivot and having fixed fulcrum points. the connections of said piston type hydraulically operated means for moving the pivots of said levers along a straight path, and means for causing the fulcrum points of said last named levers to move at a predetermined angle to said straight path so that equal increments of piston displacement of said hydraulically operated means will produce equal increments of lift of said body.

GLENWAY MAXON, JR. 

